The present invention is directed to a method for manufacturing terminal contacts for thin-film magnetic heads on a substrate that is subdivided into individual substrate elements each having two write/read heads. The substrate surface is covered surface-wide with an electrically conductive permalloy layer that at least has a plurality of contact locations with contact lugs directed toward the magnetic head. The permalloy layer is structured by ion beam etching using a metallic mask. The structured permalloy layer is covered surface-wide with a protective aluminum oxide layer except for the contact locations that are provided for the attachment of a bonding wire to an electrodeposited gold film.
The manufacture of reinforced terminal contacts such as, for example, contacting interconnects on micro-chips in integrated circuit technology, is a technological process step that is most practically, directly incorporated into an entire manufacturing process of an integrated electronic module. This contacting process, however, frequently has a disadvantage which is related to bonding techniques. The contact spacings are widened for the intended terminal contacts because the distance between the contacts is too small and the contacts must be formed with a reinforcement at the same time. This situation also occurs in thin-film magnetic head technology. Therein, windows are let into a relatively thick layer applied to a substrate and serve as a mask. These windows define the locations for reinforced contact locations at the ends of a plurality of contact lugs of the magnetic heads. The technological process for the manufacture of such thin-film magnetic heads should therefore be designed such that the magnetic heads can be simply contacted or provided with a bonding wire so that they can also be tested. Moreover, the technological requirements for the photolithic manufacture of the reinforced terminal contacts should be only insignificantly increased due to additionally required process steps.
Thus, a method for the manufacture of thin-film magnetic heads is feasible wherein contact windows are let into an approximately 50 .mu.m thick protection layer of aluminum oxide with a chemically soluble space-holder at the end of the photolithographic process. After the contact window has been laid bare in the protective layer, the exposed contact surface is gold-plated. To that end, a gold cover layer is electrodeposited surface-wide onto the substrate. Before bonding, the gold cover layer is again removed in the area of the contact surface that has been laid bare and gold-plated and a bonding needle with a bonding wire is subsequently positioned into the contact window. The critical disadvantages of the described method also lie therein. First, the surface-wide application of the gold coat is uneconomical since it is only required in punctiform fashion and, second, the adjustment of the bonding wire into excessively small contact windows is difficult. This is difficult because the wall of the contact window may be contacted during adjustment resulting in an increase in the risk of failure of the thin-film magnetic heads.